Motor and inverter cooling structure

Abstract

To prevent refrigerant liquid and oil from entering an inner side of an inverter case.SOLUTION: A cooling structure 1 of a motor and an inverter includes: a motor case 2; an inverter case 3 assembled to a lower side of the motor case 2 in a vertical direction; a connection member 4 for electrically connecting the motor and the inverter; a first seal member 5 which seals between the motor case 2 and the connection member 4; a second seal member 6 for sealing between the inverter case 3 and the connection member 4; a first flow path 7 for circulating cooling water 15 between the motor case 2 and the inverter case 3; and a third seal member 8 for sealing the first flow path 7. A relief space 9 communicating with the outside of the motor case 2 and the inverter case 3 is provided among the third seal member 8, the first seal member 5, and the second seal member 6, in an assembly part 16 of the motor case 2 and the inverter case 3.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a cooling structure for a motor and an inverter that cools or insulates or provides heat insulation between a motor case that houses a motor and an inverter case that houses an inverter or the like that controls the motor. [Background technology]

[0002] Patent Document 1 describes an invention related to a cooling structure for an inverter and a capacitor that are housed integrally with a motor inside a motor housing (motor case). In the cooling structure described in Patent Document 1, an inverter is disposed below the motor in the vertical direction. The motor housing and a case (inverter case) that houses the inverter are integrally formed. A flow path for circulating a liquid refrigerant is provided between the motor and the inverter. By circulating the refrigerant between the motor and the inverter, the refrigerant cools the motor and the inverter, and also blocks the transfer of heat from the motor to the inverter, preventing the inverter from being heated by the heat of the motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-131672 A Summary of the Invention [Problem to be solved by the invention]

[0004] When the motor case and the inverter case are integrally formed and the motor and the inverter are disposed close to each other as in the configuration described in the above Patent Document 1, a terminal block is usually provided for forming an electrical connection between the motor and the inverter. For example, in the conventional configuration example shown in FIG. 1, an inverter case 103 that houses a power control unit (PCU) 102 including an inverter is assembled to the lower surface of a motor case 101 in the vertical direction (the bottom surface on the lower side in the vertical direction in FIG. 1). The inverter case 103 is attached to the motor case 101 by, for example, bolt fastening (not shown), and the motor case 101 and the inverter case 103 are integrated. A terminal block 104 is installed between the motor case 101 and the inverter case 103. The terminal block 104 constitutes an electrical connection member between the motor (not shown) and the power control unit 102, and in the example shown in FIG. 1, a bus bar 105 and a bus bar 106 that are connected to the terminal block 104 are used to electrically connect the motor and the power control unit 102.

[0005] As shown in FIG. 1, oil 107 for cooling and lubricating the motor is poured into the motor case 101. Therefore, a seal member 108 is attached to the connection portion between the motor case 101 and the terminal block 104 in order to prevent the oil 107 from leaking from the motor case 101. A seal member 109 is also attached to the connection portion between the inverter case 103 and the terminal block 104 in order to prevent the oil 107 and water from entering the inside of the inverter case 103. As with the cooling structure described in the above Patent Document 1, a flow path 111 for circulating cooling water (or refrigerant liquid) 110 is formed between the motor case 101 and the inverter case 103 in order to block the transfer of heat from the motor to the power control unit 102. In the example shown in FIG. 1, the flow path 111 is formed by recesses 101b and 103b formed in mating surfaces 101a and 103a of the motor case 101 and the inverter case 103, respectively. Therefore, a seal member 113 is attached to a mating portion 112 where a mating surface 101a of the motor case 101 and a mating surface 103a of the inverter case 103 are in close contact with each other, in order to prevent the cooling water 110 from leaking from the flow passage 111.

[0006] In the conventional configuration as shown in the above Patent Document 1 and FIG. 1, for example, if a defect occurs in the seal member 113 between the motor case 101 and the inverter case 103 and the cooling water 110 leaks, the cooling water 110 flows from the joint 112 between the motor case 101 and the inverter case 103 into the connection between the inverter case 103 and the terminal block 104. As a result, the cooling water 110 accumulates above the seal member 109 between the inverter case 103 and the terminal block 104 (outside the inverter case 103). Similarly, if a defect occurs in the seal member 108 between the motor case 101 and the terminal block 104 and the oil 107 leaks, the oil 107 also accumulates above the seal member 109 between the inverter case 103 and the terminal block 104 (outside the inverter case 103). In such a case, if a defect also occurs in the seal member 109 between the inverter case 103 and the terminal block 104 , the leaked cooling water 110 or oil 107 may enter the inside of the inverter case 103 .

[0007] This invention has been devised with an eye on the technical problems described above, and aims to provide a cooling structure for a motor and an inverter that can appropriately suppress the transfer of heat from the motor to the inverter, and can prevent or suppress the infiltration of refrigerant liquid or oil leaked due to poor sealing, etc., into the inside of a case that houses an electronic device such as an inverter. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention provides a cooling structure for a motor and an inverter comprising: a first case (e.g., a motor case) that houses a motor; a second case (e.g., an inverter case) that houses at least an inverter (and also, for example, a PCU or other electronic device) that controls the motor and is assembled integrally with the first case below the first case in the vertical direction; a connection member (e.g., a terminal block) that is disposed between the first case and the second case and electrically connects the motor and the inverter; a first seal member that seals the space between the first case and the connection member; a second seal member that seals the space between the second case and the connection member; and a first flow path that is formed between the first case and the second case and that allows a refrigerant liquid (e.g., cooling water, antifreeze liquid, etc.) to flow, the refrigerant liquid flowing in the first flow path providing thermal insulation or thermal insulation between the first case and the second case or suppressing heat transfer. It is a structure, The first flow path is In the vertical direction The first case contacts the second case Level 1 1 mating surface, and the first case In the vertical direction The second case contacts the first case Level 1 a recess formed in at least one of the first and second mating surfaces, and a third seal member that seals between the recess and a mating portion where the first and second mating surfaces come into contact with each other when the second case is assembled to the first case, and a relief air space communicating with the outside of the first case and the second case is provided between the third seal member and the first seal member and the second seal member at the mating portion. a plate-shaped cover member is attached to the lower side of the second case in the vertical direction, a second flow path is formed between the lower surface of the second case and the cover member, and a third flow path is formed along a side surface of the second case for distributing the refrigerant liquid that has flowed through the second flow path from the second flow path to the first flow path. The present invention is characterized in that

[0009] The escape space in the present invention may have a liquid reservoir portion recessed vertically downward from the second mating surface of the mating portion. Effect of the Invention

[0011] The motor and inverter cooling structure of this invention is intended for a configuration in which a first case housing a motor and a second case housing an electronic device including an inverter are assembled together, and a first flow path for flowing a liquid refrigerant (refrigerant liquid) is provided at the joint between the first and second cases. By flowing the refrigerant liquid in the first flow path, the motor and inverter are cooled, and the transfer of heat from the motor to the inverter is blocked, making it possible to prevent the inverter from being heated by the heat of the motor.

[0012] In the configuration of the motor and inverter cooling structure of the present invention, a connection member is disposed at the joint between the first case and the second case. The connection member is, for example, a terminal block or a bus bar that penetrates the first case and the second case to electrically connect the motor and the inverter. Therefore, a first seal member and a second seal member are provided between the first case and the connection member and between the second case and the connection member to ensure the liquid-tightness or shielding property of the first case and the second case, respectively. Also, a third seal member is provided to ensure the liquid-tightness of the first flow path at the joint between the first case and the second case.

[0013] The sealing members of the above-mentioned parts may have a sealing failure due to the influence of aging, etc., and when such a sealing failure occurs, for example, the oil in the first case or the refrigerant liquid in the first flow path may infiltrate into the inside of the second case. Therefore, in the cooling structure of the motor and inverter of the present invention, an escape space is formed between the third seal member and the first and second seal members at the joint between the first and second cases. The escape space is communicated with the outside of the first and second cases, or is open or open. Therefore, even if the refrigerant liquid leaks from the first flow path due to a defect in the third seal member, the leaked refrigerant liquid flows out from the escape space to the outside without stagnating around the second seal member, i.e., between the second case and the connecting member. Or, the refrigerant liquid flows out to the outside after stagnating once in the escape space. Similarly, even if oil or the like leaks from the first case due to a defect in the first seal member, the leaked oil or the like will flow out from the relief space to the outside without staying around the second seal member, i.e., between the second case and the connecting member, or will stay temporarily in the relief space before flowing out to the outside.

[0014] Therefore, the cooling structure for the motor and inverter of the present invention can appropriately suppress the transfer of heat from the motor to the inverter, and can also prevent or suppress the intrusion of refrigerant liquid, oil, etc. that has leaked due to a sealing defect or the like into the inside of the second case that houses electronic devices such as the inverter. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a cross-sectional view for explaining a problem with the cooling structure for a motor and an inverter according to the present invention, showing a conventional configuration in which the "escape space" according to the present invention is not provided. [Diagram 2]FIG. 1 is a diagram for explaining the configuration of the cooling structure for the motor and inverter of the present invention, and is a cross-sectional view showing the cases (first case and second case) that house the motor and inverter that are the subject of the present invention, and the "escape space" of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the accompanying drawings. Note that the following embodiment is merely an example of a specific embodiment of the present invention, and is not intended to limit the present invention.

[0017] An example of a cooling structure for a motor and an inverter in an embodiment of the present invention is shown in Fig. 2. The cooling structure 1 shown in Fig. 1 includes a motor case 2, an inverter case 3, a connection member 4, a first seal member 5, a second seal member 6, a first flow path 7, a third seal member 8, and an escape space 9.

[0018] The motor case 2 is a case or housing that houses a motor (not shown) and corresponds to a "first case" in the embodiment of the present invention. Oil 10 is poured into the motor case 2 to cool and lubricate the motor.

[0019] The inverter case 3 is a case that houses at least an inverter (not shown) and corresponds to a "second case" in the embodiment of the present invention. In the embodiment shown in Fig. 2, the inverter case 3 houses a power control unit (PCU) 11 that includes an inverter. The inverter case 3 is attached to the lower surface of the motor case 2 in the vertical direction (the lower bottom surface in the up-down direction in Fig. 2). The inverter case 3 is attached to the motor case 2 by, for example, bolt fastening (not shown), and the motor case 2 and the inverter case 3 are integrated.

[0020] 2, the connection member 4 is composed of a terminal block 12, a bus bar (or conductor) 13 connected to the terminal block 12 and electrically connecting the terminal block 12 and the motor, and a bus bar (or conductor) 14 connected to the terminal block 12 and electrically connecting the terminal block 12 and the power control unit 11. The connection member 4 is installed between the motor case 2 and the inverter case 3.

[0021] The first seal member 5 seals the gap between the motor case 2 and the connection member 4. As described above, oil 10 is poured into the motor case 2. Therefore, in order to ensure the liquid-tightness of the motor case 2 and prevent the oil 10 from leaking from the motor case 2, the first seal member 5 is attached to the connection portion between the motor case 2 and the connection member 4, specifically, between the motor case 2 and the terminal block 12.

[0022] The second seal member 6 seals the gap between the inverter case 3 and the connection member 4. As described above, the inverter case 3 is a case that houses electronic devices including an inverter, and it is necessary to prevent foreign matter such as oil, water, or dust from entering the inside of the inverter case 3. Therefore, in order to ensure the shielding or waterproof / dustproof properties of the motor case 2 and to prevent foreign matter from entering the inside of the inverter case 3, the second seal member 6 is attached to the connection portion between the inverter case 3 and the connection member 4, specifically, between the inverter case 3 and the terminal block 12.

[0023] The first flow path 7 is formed between the motor case 2 and the inverter case 3, and allows the cooling water (i.e., refrigerant liquid) 15 to flow. The first flow path 7 is configured by a recess formed in at least one of the first mating surface 2a of the motor case 2 facing the inverter case 3 and contacting the inverter case 3, and the second mating surface 3a of the inverter case 3 facing the motor case 2 and contacting the motor case 2. In the embodiment shown in FIG. 2, the first flow path 7 is formed by the recess 2b formed in the first mating surface 2a of the motor case 2 facing the inverter case 3 and contacting the second mating surface 3a of the inverter case 3, and the recess 3b formed in the second mating surface 3a of the inverter case 3 facing the motor case 2 and contacting the first mating surface 2a of the motor case 2. By flowing the cooling water 15 through this first flow path 7, the motor and the power control unit 11 are cooled, and the transfer of heat from the motor to the power control unit 11 is blocked or suppressed.

[0024] The third seal member 8 is attached to a mating portion 16 where the first mating surface 2a of the motor case 2 and the second mating surface 3a of the inverter case 3 come into contact with each other when the inverter case 3 is assembled to the motor case 2, and seals the gap between the recess 2b of the motor case 2 and the recess 3b of the inverter case 3. In other words, the first flow passage 7 has the recess 2b formed in the first mating surface 2a of the motor case 2, the recess 3b formed in the second mating surface 3a of the inverter case 3, and the third seal member 8 that seals the mating portion 16 where the first mating surface 2a and the second mating surface 3a come into contact with each other and the recess 2b and the recess 3b when the inverter case 3 is assembled to the motor case 2. The third seal member 8 ensures the liquid-tightness of the first flow passage 7 at the mating portion 16, and prevents the cooling water 15 from leaking from the first flow passage 7.

[0025] The escape space 9 is formed between the third seal member 8 and the connection member 4, i.e., between the third seal member 8 and the first seal member 5 and the second seal member 6, at the joint 16 between the motor case 2 and the inverter case 3 as described above. The escape space 9 is in communication with, or is open to, the outside of the motor case 2 and the inverter case 3. Furthermore, in the embodiment shown in FIG. 2, the escape space 9 has a liquid reservoir 9a. The liquid reservoir 9a is a portion recessed downward in the vertical direction from the second mating surface 3a of the joint 16 in the escape space 9, and is formed so as to be able to store a certain amount of the cooling water 15 leaking from the first flow path 7 or the oil 10 leaking from the motor case 2.

[0026] As described above, the first seal member 5, the second seal member 6, and the third seal member 8 may have a sealing failure due to deterioration caused by aging or processing failure. If such a sealing failure occurs, for example, the oil 10 in the motor case 2 and the cooling water 15 in the first flow path 7 may infiltrate into the inside of the inverter case 3. In response to this, the cooling structure 1 in the embodiment of the present invention is provided with the escape space 9 as described above. The escape space 9 is formed between the third seal member 8 and the first seal member 5 and the second seal member 6 at the joint 16 between the motor case 2 and the inverter case 3, and is connected to the outside of the motor case 2 and the inverter case 3. Therefore, even if the cooling water 15 leaks from the first flow path 7 due to a failure of the third seal member 8, the leaked cooling water 15 does not stagnate at the upper part of the second seal member 6, i.e., the connecting portion between the inverter case 3 and the connecting member 4, but flows out from the escape space 9 to the outside. Alternatively, the oil may temporarily accumulate in the liquid reservoir 9a of the relief space 9 before flowing out. Similarly, even if a defect in the first seal member 5 causes oil 10 to leak from the motor case 2, the leaked oil 10 will flow out from the relief space 9 to the outside without accumulating above the second seal member 6, i.e., in the connecting portion between the inverter case 3 and the connecting member 4. Alternatively, the oil may temporarily accumulate in the liquid reservoir 9a of the relief space 9 before flowing out.

[0027] In the embodiment shown in FIG. 2, the cooling structure 1 includes a second flow path 17 and a third flow path 18 in addition to the first flow path 7 described above.

[0028] The second flow path 17 is provided on the lower surface of the inverter case 3 in the vertical direction (the lower bottom surface in the up-down direction in FIG. 2), and allows the coolant 15 to flow. Specifically, a plate-shaped cover member 19 is attached to the lower surface of the inverter case 3, and a recess 3c formed on the lower surface of the inverter case 3 and a recess 19a formed in the cover member 19 allow the coolant 15 to flow through the second flow path 17. The second flow path 172, the cooling structure 1 is configured such that cooling water 15 is supplied to the second flow passage 17 from outside the cooling structure 1.

[0029] The third flow path 18 is formed, for example, along a side surface of the inverter case 3, and connects the second flow path 17 to the first flow path 7. Therefore, the third flow path 18 causes the cooling water 15 that has flowed through the second flow path 17 to flow from the second flow path 17 toward the first flow path 7. In the embodiment shown in FIG. 2, the cooling water 15 is configured to be discharged from the third flow path 18 to the outside of the cooling structure 1.

[0030] By providing such second flow path 17 and third flow path 18, the cooling performance of this cooling structure 1 can be improved, and the inverter and power control unit 11 can be appropriately cooled.

[0031] Therefore, according to the cooling structure 1 for a motor and an inverter in the embodiment of the present invention, the transfer of heat from the motor to the inverter and the power control unit 11 can be appropriately suppressed. At the same time, by providing the escape space 9 as described above, it is possible to prevent or suppress the cooling water 15 or oil 10 leaking due to a sealing failure or the like from entering the inside of the inverter case 3 that houses the power control unit 11 including the inverter. In addition, by providing the escape space 9, the dischargeability of the cooling water 15 or oil 10 around the terminal block 12 in the connection member 4 is improved. Therefore, the durability of the second seal member 6 can be improved, and thus the durability and reliability of the power control unit 11 housed in the inverter case 3 can be improved. [Explanation of symbols]

[0032] 1 Cooling structure 2 Motor case (first case) 2a (Motor case) First mating surface 2b (Motor case) recess 3 Inverter case (second case) 3a (Inverter case) Second mating surface 3b Concave part (on the top surface of the inverter case) 3c Concave part (underside of inverter case) 4 Connection parts 5 First sealing member 6 Second seal member 7 First flow path 8 Third seal member 9 Relief space 9a (Relief space) liquid collection area 10. Oil 11 Power Control Unit (PCU) 12 Terminal block 13 Busbar (or conductor) 14 Busbar (or conductor) 15 Cooling water (refrigerant liquid) 16 Joint 17 Second Flow Path 18 Third Stream 19 Cover member 19a (Cover member) recess 101 [Prior Art] Motor case 101a [Prior Art] (Motor case) mating surface 101b [Prior Art] (Motor Case) Recess 102 [Prior Art] Power Control Unit (PCU) 103 [Prior Art] Inverter Case 103a [Prior Art] (Inverter case) mating surface 103b [Prior Art] (Inverter case) recess 104 [Prior Art] Terminal block (electrical connection member) 105 [Prior Art] Busbar 106 [Prior Art] Busbar 107 [Prior Art] Oil 108 [Prior Art] Sealing member 109 [Prior Art] Sealing material 110 [Prior Art] Cooling water (refrigerant liquid) 111 [Prior Art] Flow Channel 112 [Prior Art] Joint 113 [Prior Art] Sealing Materials

Claims

1. A cooling structure for a motor and an inverter comprising: a first case that houses a motor; a second case that houses at least an inverter that controls the motor and is assembled to a lower side of the first case in a vertical direction; a connection member that is arranged between the first case and the second case and electrically connects the motor and the inverter; a first seal member that seals the gap between the first case and the connection member; a second seal member that seals the gap between the second case and the connection member; and a first flow path that is formed between the first case and the second case and through which a refrigerant liquid flows, wherein the refrigerant liquid flowing through the first flow path provides thermal insulation or thermal insulation between the first case and the second case, The first flow path is a recess formed on at least one of a first horizontal mating surface of the first case, which faces the second case in a vertical direction and comes into contact with the second case, and a second horizontal mating surface of the second case, which faces the first case in a vertical direction and comes into contact with the first case; a third seal member that seals a gap between the recess and a mating portion where the first mating surface and the second mating surface come into contact with each other in a state in which the second case is assembled to the first case; and having an escape space communicating with the outside of the first case and the outside of the second case is provided between the third seal member and the first seal member and between the third seal member and the first seal member and the second seal member at the mating portion; A plate-shaped cover member is attached to a lower side of the second case in the vertical direction, A second flow path is formed between a lower surface of the second case and the cover member, A third flow path for circulating the refrigerant liquid that has flowed through the second flow path from the second flow path to the first flow path is formed along a side surface of the second case. A cooling structure for a motor and an inverter comprising:

2. 2. The cooling structure for a motor and an inverter according to claim 1, The relief space is The second mating surface of the mating portion has a liquid reservoir recessed downward in a vertical direction. A cooling structure for a motor and an inverter comprising:

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